# Oust Fan Replacement Project - PIF



## tstein (Apr 19, 2011)

As a newbie (still in my 5 day trial period) and having read tons over the last week I have been impressed with the wealth of info and contributions from others as well as the general PIF attitude that is very refreshing.

So in the PIF spirit, I hereby commit on the PUFF bible to develop a "open source" oust fan replacement. My employment background is in electrical engineering. I suspect there are other folks with some electrical knowledge that can certainly help.

I expect, with part lead times, work schedules, and smoking, that this may take a month or two to complete. 

Being as I can't find a single place to purchase an OUST fan, I could use your help in determining what the requirements are. 

How does this look as far as requirements?
- AA powered. Double AA cell would probably be preferable if discharge duration is improved.
- Small fan capable of roughly <1cfm
- Fan needs to be inaudible from outside of enclosure (PWM controlled)
- Timer must turn fan on for 5 minutes every hour automatically
- Design needs to be neat - i.e. PCB mounted to fan
- Needs to mount on plastic and wood or stand up on its own
- All parts need to be off the shelf and very available. Preferably the ability to use standard PC fans
- Sub $20 in cost. Preferably less

Nice To haves:
- Some alert that the battery is getting weak
- Adjustable fan speed 

Next Steps:
- Order several off the shelf fans and evaluate air flow and sound at anticipated voltage.

Thoughts\Input on the project?


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## Seasick Sailor (Jan 3, 2011)

All I can offer in way of support is the promise to purchase a couple of the finished product.

I have no electrical experience at all.

I am interested to see what some of our fellow BsOTL will contribute. There are many very talented people in this community.


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## WyldKnyght (Apr 1, 2011)

This is what I'm going to do in my Wineador, hopefully you can use some of these ideas to incorporate in your plans.

I'm going to use a laptop cooling fan in a 2" drawer with no bottom, I will have to do some wiring to fit the USB connector through the small hole and into an adapter to convert to electrical (I have purchase a USB to AC adapter for this) as well I have to add an electrical timer (which I am going to buy at Canadian tire for around $20)so it's not running all the time.



Hope this helps


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## Herf N Turf (Dec 31, 2008)

Craig,

Wouldn't it be easier, cheaper and simpler to simply splice it into an old, unused cell phone charger?


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## WyldKnyght (Apr 1, 2011)

Herf N Turf said:


> Craig,
> 
> Wouldn't it be easier, cheaper and simpler to simply splice it into an old, unused cell phone charger?


In essence that is what I'm going to do, the cord won't be long enough so I'm gonna cut it and feed it through the hole then splice it to a longer cable to the adapter in the wall. All the items were purchased on ebay for less than $10 total.

I'm not an electrician, I'd love to know if I can reduce the speed of the fans and then bypass the timer that way at a lower voltage I can run them constantly


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## Herf N Turf (Dec 31, 2008)

ah, gotcha! I guess there's "more than one road to Rome".


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## jcazz (Apr 2, 2011)

I've thought about using an Audrino with some power transistors to build a diy fan package. Can't get the price <$20 with the Audrino, but you could program some crazy-accurate schedules.


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## bbasaran (Mar 20, 2011)

This thread is a very needed one (for me at least). I would add into the list a timer and maybe an extra idea to use the sistem for the RH regulation?


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## jcazz (Apr 2, 2011)

If you built a microcontroller you could trigger the fans on time or humidity. Audrino's run about $20 for the controller. I bet another $20-$30 would add all needed electronics and maybe a humidity sensor.


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## tstein (Apr 19, 2011)

All good ideas. Yep, this would be microcontroller based with plenty of available I/O so additional fans and integration with a honeywell sensor would be possible in the future. I was thinking these kinds of features would be more of a version 2.0 update....I think solving the most serious problem of a Oust replacement would be priority one with features such as humidity reading would come later.

So in volume, we are probably talking about something in the range of:
PCB - $2
Fan - $3
FET - $1
Micro & Digital Circuit - $3
Misc Mechanical - $4

Something around $13 BOM.


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## tstein (Apr 19, 2011)

WyldKnyght said:


> In essence that is what I'm going to do, the cord won't be long enough so I'm gonna cut it and feed it through the hole then splice it to a longer cable to the adapter in the wall. All the items were purchased on ebay for less than $10 total.
> 
> I'm not an electrician, I'd love to know if I can reduce the speed of the fans and then bypass the timer that way at a lower voltage I can run them constantly


You can reduce the speed of the fan by either reducing the voltage from the USB 5V down to something lower OR by using a PWM controlled output.

Since your splicing anyway, you might want to splice in 3VDC (or less) and your fan should run slower\quieter.


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## asmartbull (Aug 16, 2009)

All good info, but if you are doing this for a cooler, let nature 
do its thing.....
Seasoned beads/KL on the bottom
Dry beads/ KL on the top.
Good to go..............


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## Herf N Turf (Dec 31, 2008)

asmartbull said:


> All good info, but if you are doing this for a cooler, let nature
> do its thing.....
> Seasoned beads/KL on the bottom
> Dry beads/ KL on the top.
> Good to go..............


That's just too simple, Al. Come on! This is a geek thread. No room for us, "Improvise and adapt guys" haha


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## tstein (Apr 19, 2011)

Agreed. Too simple  I want to feel the air move!!

So, microcontroller choice. The ATtiny43U looks ideal as it's made specifically to run directly from a AA and contains all the bells and whistles that would be needed. The part runs about $1.

Features include direct AA connection without voltage regulator, super low power, 2 PWM outputs (two fans), ADC inputs which could be used for reading a humidity sensor, and roughly 13 other I/O that can be used for LED\LCD\Other. 

This part would keep the BOM very cheap and may allow for a <$10 solution. 

PS Don, I'm unable to PM yet so can't reply.


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## aroma (Apr 12, 2010)

Looks like a fun project. Atmel makes good stuff, amazingly cheap. I helped my kid do a very cool science fair project using an Atmel Butterfly a few yrs back.

I'd be interested in this if I didn't already have a fan solution ready to go, using a scrounged Christmas tree timer and computer fan and a $13 regulated, adjustable-voltage wall wart from Amazon. (Although my wineador has been so stable using only beads, for now, that I haven't yet bothered to install it.)

I'd recommend you make your design flexible enough to work with larger fans and larger batteries / power supplies.


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## Tritones (Jun 23, 2010)

I can send you an Oust fan if you want one ...


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## bbasaran (Mar 20, 2011)

*Tritones* a very kind offer but I guess this project will help more people. I will search for fan and timer options. And the Idea with a cell phone charger is really cool!


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## Seminole (Apr 9, 2010)

Tritones said:


> I can send you an Oust fan if you want one ...


PM sent...


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## Boston Rog (Jan 5, 2011)

Nice i will have to watch i need a small fan in my cooler.


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## bbasaran (Mar 20, 2011)

Lately several threads are opened with similiar themes. Maybe we should add them into one bigger thread?


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## Tritones (Jun 23, 2010)

Seminole said:


> PM sent...


PM received and replied. :biggrin:


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## Jesus Quintana (Apr 15, 2011)

I'm intrigued with the ATtiny43U. I'm sticking to my pc fan/butchered 12v phone charger/wall timer plan for now, but watching the developments on here with great interest. :smoke2:


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## tstein (Apr 19, 2011)

Just as a quick update:

- Preliminary calculations show long ass runtime on single AA (will have better idea later)
- I've ordered development tools and some preliminary parts (ETA Wednesday)
- Written about 80% of the software in the meantime
- Ordered a number of fans that are available in high volumes to play with. (ETA Thursday)

Next steps:
- Finish software - about 4 hours of work
- Test fans on bench power supply to identify optimal speed\voltage

Also, I went ahead and ordered a bunch of precision humidity sensors. After the fan project, I plan to rig up Coleman 150qt with and without fans to see how necessary this really is or isn't. I'll log the data from all the sensors.


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## EARN (Feb 22, 2011)

This sounds awesome. Ive been looking for a fan solution for my fridgador. im anxious to find out the results.


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## WyldKnyght (Apr 1, 2011)

tstein said:


> Just as a quick update:
> 
> - Preliminary calculations show long ass runtime on single AA (will have better idea later)
> - I've ordered development tools and some preliminary parts (ETA Wednesday)
> ...


Something you may want to include is the frame being adjustable ( ie if it has support legs) to be able to adjust to any box, coolidor or wineador.

Just an idea


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## tstein (Apr 19, 2011)

Yeah, the mounting is on my mind, but I haven't thought about it much. I figure I'll solve that problem after I get the PCB size\mounting and fan selected. 

The mounting methods available definitely need to be flexible. It's gonna need to be able to sit upright on it's own as well as provide a few good other mounting options. A simple magnetic mount may be a good option as it should stick to plastic, wood, etc and still allow the battery to be changed easily. 

If there are any other ideas, feel free to toss them out!


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## J.C. (Apr 4, 2009)

Subscribed! This will be very interesting to follow as I've been looking for a fan solution that I can use in my new cabinet that doesn't require a bulky wall timer to take up space on the cabinet outlet.

I might have missed this in a previous post, but will your design allow for the user to wire it to a 12v brick adapter instead of using batteries?

Thanks so much for dedicating your time to this project!


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## mrmikey32 (Dec 7, 2010)

Damn, wish i had seen this before. 

I am a POS engineer(cash registers, not pieces of shit)

I deal with this crap a lot. 

I thought about doing this, via arduino.

thats about as far as i got.


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## bbasaran (Mar 20, 2011)

*tstein* after all reading and thinking about this subject I believe that the battery option is not our solution we need more power to get the job done.


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## mrmikey32 (Dec 7, 2010)

bbasaran said:


> *tstein* after all reading and thinking about this subject I believe that the battery option is not our solution we need more power to get the job done.


I would go with a small lithium cell, or possible solar cell mounted on top of the humidor. I would even bet you could use induction charging if done right....


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## J.C. (Apr 4, 2009)

There will be those who have coolidors and large desktop humidors that would like this to run off batteries, while there will be others with large cabinets or towers that have AC outlets available that would like this to run off the plug.

If this fan could be designed to run off both types of power, it would meet everyones requirements instead of picking only one source of power and appealing to half the crowd. I know myself that I would be interested to know if multiple units could be connected together and run off an outlet.

tstein, I know you probably have a lot of work ahead of you, but just remember we all appreciate it!


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## Coop D (Oct 19, 2008)

I would like something that moves more air then an Oust without losing anymore spave in my x-large desktop


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## lgomez (Aug 9, 2009)

i like where this might be going


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## WyldKnyght (Apr 1, 2011)

One thing we all have to remember is we also have to keep the price point down, the more features we add the more the cost will go up, and if it's too expensive, most people will still use their current methods. The reason people use Oust and PC fans is that they are inexpensive and relatively easy to setup.


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## tstein (Apr 19, 2011)

Craig is correct. By adding other features, the price would push this outside of the inexpensive Oust alternative. So first revision will be battery powered only.

I think a second variant might be appropriate down the line, which should include either a battery or a DC power supply. This second variant will cost more, but might have some cool features we could throw at it like humidity sensors, LCD, etc. I think it's best to stay focused on the oust replacement for now.

So, here is my status update:
1) Received my fan samples. I've identified a 12VDC fan that runs super quiet at 3.0VDC (our system voltage) at only 17mA. The fan is readily available.
2) With a theoretical system current draw of 20mA when the fan is on or roughly 1uA off, we are looking at maybe 2-3 months runtime per battery. So doubling up on the batteries could go 6 months. Nice!
3) No real other progress yet. Work will be busy through next week so I may be inactive till later next week.

HOWEVER, does anybody have an oust fan that I could evaluate? I'd like to see how the CFM compares to what I'm thinking will work.


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## bbasaran (Mar 20, 2011)

Ok the theme about prices might be right for most of us; but I believe it first must be do the job well. And as far I can see this is not possible with battery powered devices. This is my thinking, might be right or wrong.

Well Today I tried several fan from a mini DC Brushless one to a bigger arctic cooling and I searched for several options. I had one Idea and it works perfect. But before this one I will share other options:

How about to make/use a solar powered device? Like this one;
















4.98 USD : $4.98 - Solar Powered Cooling Fan for Hats/Caps - Solar Powered Gadgets

Or a duct fan?:
















okay, okay its a bit high priced 86.70 USD: $86.70 - 68mm Electric Duct Fan + 3900KV Motor - Silver Black - R/C Helicopters

And my solution.







I attached over usb and it works perfect for me.


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## Coop D (Oct 19, 2008)

All look really big compared to the size of an Oust fan. Could just be the pictures


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## aroma (Apr 12, 2010)

If you have a power supply, the obvious choice, and one widely used in wineadors, is a computer fan. They are cheap, reliable, and quiet.

The one I scrounged is an 80mm one, rated at 100ma @ 12 VDC. Computer builders often undervolt them, to reduce noise (with the understanding that airflow is also reduced). I'm not sure what its actual draw is at 12V, 7V, 5V, etc.


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## bbasaran (Mar 20, 2011)

*Coop D* I dont know the sizes but I believe those will produce more airflow then an Oust fan. I only use the fan part of an old hairdryer and I will post soon images and sizes for compare. But I must say, I use it on the top and just one shelf under I have a DW cup, the air is direct blown into this cup and I can register in minutes the RH changes.

*aroma* Your right fans for computer are cheaper, Im sure they will be quiet. I have one 17 cm (6.7") laptop cooler fan in the bottom very quite around 600 rpm. Just tested the hairdryer fan and it was well for me, a bit noice is ok; I will try to make it quiter (adding a bit oil and clear the device from dust and etc.) plus Timer I believe this will be my solution in the end.


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## Jesus Quintana (Apr 15, 2011)

Phillip, any further developments on this?



mrmikey32 said:


> Damn, wish i had seen this before.
> 
> *I am a POS engineer(cash registers, not pieces of shit)*
> 
> ...


mrmikey, that keeps making me laugh!


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## Jenady (Nov 23, 2009)

Coop D said:


> I would like something that moves more air then an Oust without losing anymore spave in my x-large desktop


My thoughts exactly. I have two Oust fans in each of my large coolers and one modified Oust in my biggest Waxing Moon humi. I am giving up a lot of space and using a lot of D cells.

I am looking forward to your results.


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## tstein (Apr 19, 2011)

Hey Gents,

Sorry for the lack of replies\updates. I am still making progress but waiting for some parts to arrive.

So, the fans evaluated are all working well. The driver board circuit will accommodate any 5VDC fan. I'm laying out the PCB now, but the board will run up to 4 fans. Pretty much any off the shelf fan will work, but obviously they vary in size\RPM\sound. The software turns the fans on at 5VDC and then scales down the voltage a bit to improve battery life. Very reliable operation.

As far as battery life, I don't have accurate measurements yet, but a single AA should net 60-90 days life for the fan I've selected. A single D cell will run the fan for a year and 40 days  Each additional fan will decrease the run-time. 

So, progress continues but very slowly. This and last week have been a bit busy and I expect that to continue for a bit. This is still looking like a 1-2 month project for me.


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## Reino (Sep 13, 2010)

Just got my wineador going. Using O fans until you get this worked out. Looking forward to further findings and solutions. I dig the year and 40 days on a D cell!


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## WyldKnyght (Apr 1, 2011)

Great work Philip, keep it up.


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## Pipedreamz (Feb 4, 2011)

How much are you planning on selling these for?


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## tstein (Apr 19, 2011)

I'll probably do a limited quantity build at cost for PUFF as an effort to PIF  Cost hasn't been worked out, but I'm still within the goal\target in my first post. 

I'll post the Bill of materials, gerbers, and software thereafter as I don't want to be in the humidor fan business long term  Hopefully some company will pick it up and make it commercial long term so there is a good\easy replacement available.


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## Pipedreamz (Feb 4, 2011)

Sorry I missed that in the first post. This is a great idea


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## bbasaran (Mar 20, 2011)

*Philip* A nice progress continues and Im sure this will have also nice results. Cant wait for further developments.


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## Torqued (May 18, 2011)

Any updates?


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## usrower321 (Mar 27, 2011)

Here is what I did. It only cost me $4.08, but I had some parts lying around.

http://www.cigarforums.net/forums/vb/cigar-accessory-discussion/292654-my-new-coolidor-fan-project-pic-heavy.html


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